Multilobal textile filaments having controlled uniform twist and fabrics prepared therefrom



Nov. 5, 1963 J. w. GIBSON, JR 3,109,273

MULTILOBAL TEXTILE FILAMENTS HAVING CONTROLLED UNIFORM TWIST AND FABRICSPREPARED THEREFROM Filed Aug. 19, 1960 3mm: JOSEPH W. GIBSON, JR.

United States Patent MULTILGBAL TEXTILE FELAMENTS HAV- ING CONTRGLLEDUNTF-SRM TWIET AND FAERECS PREPARED THEREFRQM Joseph W. Gibson, Era,Wilmington, Deh, assignor to E. l. du ?ont tie Nenrours and (Zompany,Wilmington, Del, a corporation of Delaware Filed Aug. 19, 1950, Ser. No.50,714 11 Cla ms. (Cl. 57-140) This invention relates to novel twistedmultilobal monofilaments and, more particularly, to new and improvedsheer fabrics prepared from the novel monofila-ments.

Textile filaments prepared from synthetic polymers which exhibit uniqueoptical properties in the form of luster highlight or sparkle have beenrecently introduced for use in various woven and knitted fabrics. Whenthese filaments are incorporated in tightly knitted and woven fabrics, apleasing luster and uniform highlight or sparkle is obtained. However,in preparing fabrics of sheer construction from such monofilaments ithas been difficult to achieve uniformity of luster highlight or sparkleacross the entire surface of the fabric. This non-uniformity has beenevidenced in such fabrics as sparkling nylon hosiery by areas of intensesheen and areas which exhibit neither sparkle nor sheen.

It is, therefore, an object of this invention to provide novelmonofilaments which exhibit improved optical properties when utilized infabrics of sheer construction. It is another object of this invention toprovide fabrics of sheer construction having optical properties rangingfrom an intense, uniform luster highlight or sparkle to a subdued,uniform luster highlight or sparkle. Other objects of this inventionwill be apparent from the following detailed description.

The objects of this invention are accomplished by knitting or weavingsheer fabrics from sparkling textile monofilaments of synthetic polymershaving a multilobal cross section with a uniform twist of at least about4 turn per inch. The cross sections of the sparkling monofilamentsconsist of integrally joined lobes, each of which terminates in anessentially arcuate tip. The configuration of the lobes is such that aluster highlight or sparkle is provided by the monofilament. The sheerfabrics are provided by knitting or weaving the textile monofilaments.

By sheer fabrics it is meant those in which a perpendicular projectionof the fabric onto a flat surface which is parallel .to the fabricresults in not more than about one-third of the surface being covered bythe projection of the filaments.

Surprisingly, according to the present invention, by utilizingsparkling, twisted multilobal filaments having at least 4 turn per inch,a fabric is provided which has a uniform sparkling appearance over itsentire surface. By utilizing monofilaments having from A to 7 turns perinch, the sparkle which is inherent in the filaments is uniformlydistributed throughout the fabric without a significant reduction of theunique high intensity of sparkle. By progressively increasing the twistfrom 7 to 20 turns per inch, the sparkle is gradually reduced but isvisible uniformly over the entire surface area of the fabric. Aboveabout 20 turns per inch the unique sparkle is eliminated and the fabricexhibits merely a subdued, uniform luster. The optimum number of twistsper inch for obtaining this effect may vary, depending on the particularfiber cross section, e.g., trilobal, tetralobal, or pentalobal, as wellas the denier of the filament. The twist may be alternating, i.e, an Sor Z twist; however, it must be uniform along the length of thefilament. Preferably a unidirectional S or Z twist is used. In addition,the filaments should be essentially free from crimp nodes and loops whenincorporated in the fabric.

While this invention is primarily directed to obtaining unique opticaleffects, it has been discovered that the novel twisted filaments providesignificantly improved resistance both to the formation of picks duringpreparation and finishing of the fabric and snags in the finishedfabric. The picks and snags are caused by loops of yarn being caught andbeing permanently pulled out of position without being broken. Thenumber of loops caught in a given fabric is reported as the picks orsnags in that fabric.

This invention will be morefully described in conjunction with theaccompanying drawings, in which:

FIGURE 1 is an oblique projection of a twisted trilobal monofilamentaccording to the present invention;

FIGURE 2 is an oblique projection of a twisted tetralobal monofilamentaccording to the present invention;

FIGURE 3 is a magnified view of a small section of a sheer knitstructure knitted from the twisted monofilaments shown in FIGURE 1;

FIGURE 4 is a magnified view of a small section of a sheer knitstructure knitted from twisted monofilaments similar to that shown inFIGURE 2; and

FIGURE 5 is an oblique projection of a twisted pentalobal monofilamentaccording to the present invention.

In general, the cross section of the filaments may be of any multilobalstructure having three or more integrally joined lobes, each of whichterminates in an essentially larcuate tip. The configuration must besuch that a sparkling filament is provided. Examples of such filamentsare those sparkling filaments having a trilobal cross section of thetype described in U.S. Patents 2,939,201 and 2,939,202. Trilobalfilaments having a modification ratio in the range of about 1.1 to about2.0, a tip radius ratio 'of from about 0 to about 0.85, and an arm anglein the range from about 20 to about 150 are of particular interest.Among other filament cross sections which may be utilized in preparingthe sheer fabrics of this invention are filaments of tetralobal crosssection, particularly those having a tip radius ratio of about 0.3 toabout 0.8 which are further described in the US. application of McKinneyand Stanley, Serial No. 50,725, filed concurrently herewith, andfilaments of pental'obal cross section described in Ellingsen U.S.application Serial No. 742, filed January 6, 1960'.

Spinnerets and spinning conditions suitable for preparing thesefilaments are described in the aforementioned patents and applications.The twist may be introduced into the filaments by known procedures,e.g., those (tisclosed by Stoddard et al. US. Patents 2,803,105,2,803,108, and 2,803,109. After twisting, the filaments may be treated,for example, by heating, to set the twist. The denier of the twistedmonofilaments of this invention may vary within wide limits, e.g.,deniers from 1 to or more may be used in preparing textile fabrics.Preferably, deniers in the range from 1 to about 40 are utilized inpreparing the sheer fabrics.

The following examples illustrate specific embodiments of fabrics of thepresent invention.- in theexamples, numerical descriptions, e.g., 15l%,are used to identify the total denier, number of filaments, and turnsper inch of twist of the yarn, respectively.

EXAMPLE I Womens seamless hosiery were knit on a 400-needle Scott andWilliams, Model KN, hosiery knitting machine (manufactured and sold byScott and Williams, Inc., Laconia, NH), using for the leg fabric l5l% Ztwisted nylon yarn having a trilobal cross section with a modificationratio of 1.53, a tip radius ratio of 0.36, and an arm angle of 53 Thetrilobal monofilamen-t contained 0.02% titanium dioxide. A 4( 13 /2 Zround cross section nylon yarn was used for the welt fabric,

and a 3Ol0 /2 Z round cross section nylon yarn was used in the heel andtoe. The hosiery were looped, preboarded, scoured, and dyed to a goldshade, and postboarded, using conventional procedures. The resultantgold-colored hosiery, having the twisted trilobal monofilaments in theleg fabric, exhibited a very high level of sparkle. The sparkle wasuniform throughout the leg portion.

Two sets of sirnilar hosiery were prepared as described above exceptthat in one set 15-2- 4 Z and in the other set 3(, .'2 /1 Z trilobalcross section nylon yarn, having the aforementioned parameters, wassubstituted for the monofilament tnilobal cross section yarn. Both setsof hosiery exhibited appreciably less sparkle than the monofilament yarnhosiery.

Hosiery prepared using ISA- A Z round cross section nylon yarn, usingthe aforementioned procedure, did not exhibit any sparkle and bycomparison appeared extremely dull and had low color clarity.

In a wear test, the hosiery prepared from l5-denicr (15-1) twistedmonofilament trilo-bal yarn exhibited twice the snag resistance of boththe 15 denier (15-1) monofilament round yarn hosiery and the 15-2trilobal yarn hosiery. The 15-1 twisted trilobal yarn hosiery developedsix times fewer picks in mill handling than the 151 roundyarn hosiery.

EXAMPLE II Womens full-fashioned hosiery were knit on a 60- gauge,4-position Reiner hosiery machine (manufactured and sold by RobertReiner, Inc, Weehawken, N1), us ing lS-denier monofilament trilobm crosssection nylon yarn having a modification ratioof 1.62, a tip radiusratio of 0.31, and an arm angle of 56 in the leg fabric. The yarncontained 0.3% titanium dioxide.

Four sets of hosiery were prepared using various levels of twist in themonofilament yarn. Twisting of the yarn was accomplished using a Modeldowntwister (manufactured and sold by Universal Winding (30.,Providence, R.I.). In each set of the hosiery 4013- /2 Z tri-lobal crosssection nylon yarn was used for the welt fabric and 301O /z Z trilobalcross section nylon yarn for the splicing. All of the trilobal yarns hadthe same cross sectional parameters. The hosiery were seamed,preboarded, scoured, dyed to a gold shade, finished using a resinemulsion, and postboarded, using conventional procedures. The four setsof hosiery were compared for visual appearance of the leg fabric byplacing them flat on a table. The results are recorded in the followinglarge areas of no sparkle or shccn.

Intense sparkle uniformly distributed throughout the entire leg portion.

Uniform sparkle but slightly less intense than that obtained with 1 Ztwist.

Uniform subdued luster with little sparkle remaining.

EXAldPLE 1111 Womens fu-ll-fashioned sweaters were knit on a 21- gaugeWildman full-fashioned sweater body and sleeve machine (manufactured andsold by Wildman Manufacturing Co., Norristown, Pa), using 21/2 cc. Orlon1 yarn and two ends of l5l% Z twisted trilobal nylon yarn, containing0.0 2% titanium dioxide, and having a modification ratio of 1.53, a tipradius ratio of 0.36, and an arm angle of 53. The two yarns were fed tothe machine together. The sweaters produced were seamed, scoured, and abasic black dye was used to dye the Orlon yarn in the sweaters to ablack shade. A

Registered trademark for Du Pont's acrylic fiber.

Polyamide tetralobal cross section yarns were prepared in accordancewith Example 3 of McKinney and Stanley US. application Serial No.50,725, filed August 19, 1960. The monofilarnents which contain 0.3%titanium dioxide were 15 denier, had a tenacity of 5.1 grams per denier,and had an elongation of 24%. Samples were prepared at twist levels of5, 10, 15, 20, and 35 twists per inch with a uniform alternating Z and Stwist. The twisted yarns were given a mild set, using steam at apressure of 10 pounds per square inch, for a period of ten minutesbefore coning and knitting. Seamless hosiery having the structureillustrated in FIGURE 4 were knitted. The hosiery prepared fromfilaments having twists of 5 turns per inch exhibited a uniform, highsparkle. twists of 1O, 15, and 20 turns per inch exhibited a uniformsparkle with reduced intensity. Sparkle was not present in hosieryprepared from filaments having. 35 turns per inch.

From the foregoing examples it will be apparent that the novel fabricsof the present invention exhibit unique light-reflecting propertieswhich are greatly improved as compared to the properties of fabricsprepared from multilobal multifilament yarns as well as non-twisted andround monofilaments. The uniformity of the optical properties as well asthe pick and snag resistance are outstanding.

The twisted monofilaments of this invention may be advantageously usedas an effect thread in woven, knitted, and non-woven fabrics in additionto the fabrics previously described. The number of monofilaments may bevaried as well as the pattern in which they are incorporated in thefabric. In general, the effect thread may be used in an amount from lessthan 1% by weight of the total fabric up to as much as 20% or more,depending on the fabric construction and the effect desired. Forexample, in using trilobal filaments of low twist, e.g., A to 7 turnsper inch, attractive isolated areas of uniform, high sparkle may beobtained. Fabrics may be prepared which incorporate both filaments oflow twist as well as filaments of higher twist, e.g., 7 to 20 turns perinch, with the filaments being prepared from the same synthetic polymer.It is preferable, however, to select an effect thread having a differentpolymeric composition than the filaments in the body of the fabric. Inthis manner, the two polymeric compositions can be selectively dyed toaccent the lustrous or sparkling character of the effect thread.Obviously other means may be used for accenting the effect thread. Forexample, the two filamentary materials may have differentcross-sectional configurations or the effect thread and the body threadmay be subjected to different amounts of drawing or other treatment inpreparation which will lead to differential dyeing. In general, a mostpleasing and striking effect is obtained when the effect thread is dyedto a lighter shade than the body filaments. If the effect thread and thefilaments in the body of the fabric are of the same polymer compositionthey may be dyed before conversion into a fabric by stock dyeing, dopedyeing, yarn dyeing, and the like, in order to achieve fabrics havingdifferentially dyed effects.

Stripping agent.

The hosiery having.

In preparing the products of the present invention, conventional textileadjuvants, e.g., dyes, small amounts of delusterants such as titaniumdioxide, as well as other materials may be utilized. The monofilamentsmay be prepared from a variety of synthetic polymers in addition tothose set forth in the foregoing examples such as those disclosed inU.S. Patent 2,939,201. The filaments may be subjected to conventionaltextile processing, for example, drawing, heat setting, etc., so long asthe optical properties are not destroyed.

The novel products of this invention may be employed in a wide varietyof different types of sheer fabrics. Specific examples of these productsinclude shirtings, suitings, dress and blouse fabrics, hosiery,lingerie, georgettes, tissue-failles, foulards, batistes, tricot,tulles, circular knitted goods, chiffons, sheers, crepes, casementfabrics, nets, etc. The novel filaments of this invention may also beemployed as effect threads in a wide variety of different types offabrics, including both apparel and industrial textile products.Specific examples of these products in clude shirtings, suitings, dressand blouse fabrics, hosiery, sheeting, lingeries, taifetas, georgettes,sand-Crepes, tissuefailles, foulards, broadcloths, batistes, rainwear,surah, tricot, tulles, circular knitted goods, satins, chiffons, sheers,crepes, casement fabrics, upholstery, filter cloths, ducks, beltings,webbing, braids, cordage and twine, fiber-reinforced laminates, tirecord, coated fabrics, stuffing materials, floor coverings, and tiles.The effect threads are particularly useful in the preparation of varioustypes of carpeting, e.g., tufted, chenille, Smyrna, Wilton, Saxony,Brussels, velvet, Axminster, orientals, knitted, pleated, and the like.

As many widely different embodiments of this invention may be madeWithout departing from the spirit and scope thereof, it is to beunderstood that this invention is not to be limited to the specificembodiments thereof except as defined in the appended claims.

I claim:

1. A textile fabric of sheer construction exhibiting a uniform sparklecomprised of sparkling monofilaments prepared from synthetic polymershaving a multilobal cross section, the cross section of each of saidmonofilaments consisting of from 3 to 5 integrally joined lobes each ofwhich terminates in an arcuate tip, said monofilaments having a uniformunidirectional twist throughout their lengths of from about one-quarterto twenty turns per inch along their straight axis and being essentiallyfree of crimp nodes and loops when incorporated in said fabric.

2. The fabric of claim 1 wherein said monofilaments have a trilobaicross section.

3. The fabric of claim 1 wherein said monofilaments have a uniform twistbetween one-quarter and seven turns per inch.

4. The fabric of claim 1 wherein said monofilaments have -a uniformtwist between seven and twenty turns per inch.

5. The fabric of claim 1 wherein said cross section has a t-ipradiusratio of from about 0 to about 0.85, an arm angle of from about 20 toabout and a modification ratio between about 1.1 and about 2.0.

6. A sparkling textile monofilament prepared from a synthetic polymerhaving a multilobal cross section along its length, said monofilamenthaving a uniform unidirectional twist throughout its length of fromabout onequarter to twenty turns per inch with respect to its straightaxis and being essentially free of crimp nodes and loops, said crosssection consisting of from 3 to 5 integrally joined lobes each of whichterminates in an arcuate tip.

7. The monofilament of claim 6 wherein said monofilament has a trilobalcross section.

8. The monofilament of claim 6 wherein said monofilament has a uniformtwist between one-quarter and seven turns per inch.

9. The monofilament of claim 6 wherein said monofilament has a uniformtwist between seven and twenty turns per inch.

10. The monofilament of claim 6 wherein said cross section has a tipradius ratio of from about 0 to about 0.85, an arm angle of from about--20 to about 150, and a modification ratio between about 1.1 and about2.0.

=11. A sparkling textile monofilament prepared from a synthetic polymerhaving a multilobal cross section along its length, said monofilamenthaving a uniform unidirectional twist throughout its length of at leastabout A turn per inch with respect to its straight axis and beingessentially free of crimp nodes and loops, said cross section consistingof from 3 to 5 integrally joined lobes each of which terminates in anarcuate tip.

References Cited in the file of this patent UNITED STATES PATENTS2,387,791 Hoffman Oct. 30, 1945 2,418,771 Irwin Apr. 8, 1947 2,584,944Tilles Feb. 5, 1952 2,751,747 Burleson June 26, 1956 2,843,449 RaynoldsJuly 15, 1958 2,939,201 Holland June 7, 1960 2,939,202 Holland June 7,1960 2,956,328 Faw Oct. 18, 1960 2,966,775 Seem et a1. Ian. 3, 19613,010,146 Wanthen Nov. 28, 1961 3,017,686 Breen et al. Ian. 23, 1962FOREIGN PATENTS 401,160 Great Britain Nov.-9, 1933 UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3, 109 278 November 5, 1963Joseph W. Gibson, Jr.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 6, line 4, for the claim reference numeral "1" read 2 Signed andsealed this 28th day of April 1964.

(SEAL) Attest: ERNEST W. SWIDER EDWARD J. BRENNER Attesting OfficerCommissioner of Patents

1. A TEXTILE FABRIC OF SHEER CONSTRUCTION EXHIBITING A UNIFORM SPARKLECOMPRISED OF SPARKLING MONOFILAMENTS PREPARED FROM SYNTHETIC POLYMERSHAVING A MULTILOBAL CROSS SECTION, THE CROSS SECTION OF EACH OF SAIDMONOFILAMENTS CONSISTING OF FROM 3 TO 5 INTEGRALLY JOINED LOBES